An evaluation of the Prudhoe Bay gravity drainage mechanism by complementary techniques

Conference · Fri Mar 01 04:00:00 EST 1985 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:5063341

Haldorsen, H H; Chang, D M; Creveling, D M; Mayson, H J; Rego, C A

The gravity drainage mechanism in the Prudhoe Bay Field has been evaluated by means of repeat Compensated Neutron Log (CNL) data, centrifugal gas/oil displacements in small preserved cores, and by an analytical stochastic approach. From the repeat CNL data, in-situ displacement efficiencies as observed above the advancing gas-oil contact in 50 gravity drainage wells have been estimated. A Monte Carlo-type error analysis is presented to give the range of uncertainty associated with the results. Gas/oil centrifuge displacements in small preserved cores were performed in order to validate the CNL results, and to investigate the time dependency of recovery in gassed out zones which is otherwise beyond CNL resolution. Conventional scaling theory was subsequently used to find homologous times for the reservoir and laboratory models, thus making comparisons (between CNL and centrifuge data) possible. In addition, relative permeability to oil (to be used in the analytical study) was computed from the centrifuge data. Finally, an approximate analytical description of the gravity drainage process was formulated and a Monte Carlo analysis performed to cover the wide range of values the input parameters in the equations may take on. This analysis yields a statistical distribution in displacement efficiencies at each point in time. The ''average'' behavior may be compared to the CNL and centrifuge data. The results demonstrate that the gravity drainage mechanism in Prudhoe Bay is very time-effective and yields high quantifiable displacement efficiencies. The consistency obtained among the various evaluation techniques gives confidence in the results.

• Research Organization: Sohio Petroleum Co.
• OSTI ID: 5063341
• Report Number(s): CONF-830512-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE13651
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ARCTIC OCEAN
BAYS
BEAUFORT SEA
COMPUTER CALCULATIONS
DRAINAGE
ENHANCED RECOVERY
FLUID FLOW
FLUID INJECTION
GEOLOGIC DEPOSITS
GRAVITATION
MINERAL RESOURCES
NEUTRON LOGGING
OIL FIELDS
OIL WELLS
PETROLEUM DEPOSITS
PRUDHOE BAY
RADIOACTIVITY LOGGING
RECOVERY
RESOURCES
SEAS
SURFACE WATERS
SWEEP EFFICIENCY
TWO-PHASE FLOW
WELL LOGGING
WELLS